Originally posted by ArMaP
reply to post by TrueAmerican
That's the difference between a wave created from the top to the bottom, like this one, and one created from the bottom to the top, like what happens
with earthquakes and real tsunamis.
Well actually what matters the most is the amount of water volume displaced in the action, whether by quake or glacier- or asteroid for that matter.
And a large part of that is dependent on the velocity, mass, and density of the object hitting the water. Had that been a rock faced wall, instead of
ice, those people would probably of have been killed. The wave would have been probably two to three times higher, given the exact same amount of
rock, instead of ice, falling from the same height.
The reason: density. Rock is approximately two to three times more dense than ice. And had that been rock, it would have displaced a whole lot more
water. With nowhere else to go, UP is where that water goes, as well as increased velocity vertically and laterally.
What is truly scary to think about is that in the case of Cumbre Vieja, the massive failing rock face is a mixture of volcanic rock types that all
have two to three times the density of ice. And the potential volume of the massive cliff that could collapse dwarfs what we see here. Much higher,
much bigger, much more dense.
If the whole thing were to collapse at once, (very unlikely) you can imagine, just from that little bit of ice that fell, what kind of waves CV could
produce. Lituya Bay is an example, although there are major differences in water depths and shapes of the affected areas, and that can have an effect
too. LB is about 220 meters deep whereas the base of the island of La Palma is more like 4000 meters deep. LB is also a bay, which concentrated the
massive 1,720 ft wave up the slopes. Whereas at CV/LP, there would be no such concentration, but there is a lot more water volume that can move.
About the highest quake-generated tsunami will get is 200 ft in a worst case scenario, but as we know, the volume of water behind it could be so great
that height in that case doesn't matter as much as the incredible volume of water that follows. It just keeps coming. So what's worse, a 100 ft
quake-generated tsunami, or a 1,000 ft landslide generated tsunami? That ought to keep some curious brains working for a few.
edit on Sat
Jul 21st 2012 by TrueAmerican because: (no reason given)